President-elect Donald Trump detoured from his victory tour Friday to stump for Louisiana Republican Senate candidate John Kennedy ahead of this weekend’s runoff, as the GOP aims to widen its 2017 majority in the upper chamber – and ensure an even friendlier Congress for the incoming president.

Kennedy, the state treasurer and GOP Senate candidate, introduced Trump at their Baton Rouge rally, saying “I’m running for Senate for the same reason Donald Trump ran for president: I want my country back.”

Saturday’s race between Kennedy and Democratic opponent Foster Campbell, the state public service commissioner, marks the last major election of the year – and has emerged as a postscript proxy battle between Trump and Hillary Clinton allies. Neither Kennedy nor Campbell won a majority in the November general election to replace retiring GOP Sen. David Vitter, sending the election into a runoff between the two best-placing contenders. Kennedy, leading in the polls, is considered the front-runner, but Trump was leaving nothing to chance with his visit Friday.

“We need you to go to the polls and send John Kennedy to the United States Senate,” Trump said. “If he doesn’t win, I have myself a problem in Washington.”

Republicans will have a narrow 52-48 Senate majority next year if they maintain the Louisiana seat. Vice President-elect Mike Pence also campaigned for Kennedy last week in New Orleans, saying a Kennedy win would "put an exclamation point at the end of a great American victory in 2016."

Kennedy, in his remarks, noted that they started the crowded Senate race with 24 candidates.

“If you lined up all 24 on this stage, you couldn’t pick two more different than Foster Campbell and John Kennedy,” Kennedy said. “If you took Hillary Clinton, stood her upside down and shook her, Foster Campbell would fall out of her pocket.”

Democrats have bolstered their fundraising efforts for Campbell, keeping him competitive with Kennedy on the cash-on-hand front. Both candidates are going into tomorrow’s runoff race with approximately $1.4 million.

Despite the efforts, Campbell has struggled to turn around the polls in a state where Trump decisively beat Clinton 58-38 percent. The latest RealClearPolitics average has Kennedy up by 7.5 points.

Trump also asked voters to turn out for Louisiana’s remaining congressional race Saturday. “I also need you to elect Mike Johnson to the U.S. Congress, the 4th district,” Trump stated.

FoxNews.com’s Danny Jativa and Joseph Weber and The Associated Press contributed to this report.